Urea inclusion compounds of n-alkyl oxiranes



United States Patent 3,219,654 UREA INCLUSION COMPOUNDS OF n-ALKYLOXIRANES Bruce W. Brodman, Philadelphia, and Jack Radell, Trevose, Pa.,assignors to the United States of America as represented by theSecretary of the Army No Drawing. Filed May 28, 1964, Ser. No. 371,143 4Claims. (Cl. 260--96.5) (Granted under Title 35, U.S. Code (1952), see.266) 3,219,654 Patented Nov. 23, 1965 drops of n-1,2-epoxyoctane Wereadded to 4.5 ml. of urea-methanol solution (0.15 gram urea per ml. ofmethanol) in a test tube. The tube was stoppered and shaken for 30seconds and allowed to stand at 4 C. for 24 hours. The crystals thatformed were filtered with suction and washed with 10 ml. of absoluteethanol at 4 C. No crystals formed when the urea-methanol solution wasused as a blank. In some cases tetragonal urea crystallized from theurea-methanol solution after a non-complex forming compound had beenadded.

The dried urea complex was finely ground with a mortar and pestle andapplied to the surface of a roughened glass slide. The interplanarspacings and relative intensities were obtained using an X-raydiffractometer with a Geiger tube detector at 35,000 volts andmilliamperes with a scanning rate of 1 per minute and the data wererecorded.

In preparing our urea inclusion compounds of n-1,2- epoxynonane andn-1,2-epoxydodecane, 30 drops each of the respective samples were usedin place of the n-1,2- epoxyoctane.

The following table indicates conclusively the formation of our threenovel compounds:

X-RAY POWDER PATTERNS OF UREA INCLUSION COMPOUNDS OF n-R-CHCH2 (Urea)- aInterplannr spacings in A. using CuKa radiation. Relative intensities,100 being the strongest.

presence of the complexing agent would interfere with the eventual useof the bound material. The complexes may be formed by admixing thereactants in a solvent for one of the compounds, either the host or theguest. Preferably, a mutual solvent is used. A pre-complex formationtakes place in solution. Although pre-complexing takes place in mostinstances by stirring the ingredients at room temperature, dissolutionof the materials is often accelerated and oftentimes pre-complexformation may be promoted by the use of elevated temperatures up toabout to degrees C.

We have discovered that certain members of the oxirane group, which areknown to possess mycological properties, may be trapped and stored as aguest molecule in a urea inclusion compound.

Accordingly, it is a broad object of this invention to provide new ureainclusion compounds.

Another object of the invention is to provide such compounds wherein theincluded, stored or trapped molecule is an n-alkyl oxirane.

Still another object of the invention is to provide urea inclusioncompounds wherein the stored mycologically active molecules are slowlyreleased in a humid atmosphere.

Other objects and advantages of the invention will be apparent as thedescription of the invention proceeds.

Certain members of the oxirane group are known to be mycologicallyactive. In accordance with our invention we have found thatn-1,2-epoxyoctane, n-1,2-epoxynonane and n-l,2-epoxydodecane are capableof being trapped within a urea molecule. Under proper conditions ofrelative humidity, the host urea molecules are dissolved by the moistureto permit liberation of the trapped oxirane molecule.

In the actual preparation of one of our novel compounds, a ureainclusion compound of n-1,2-epoxyoctane,

From the above X-ray diffraction data, it may be concluded thatn-1,2-epoxypentane and n-1,2-epoxyheptane (Items No. 1 and 2) failed toform urea inclusion compounds since the relative intensities at theinterplanar spacing 3.95-4.01 A. indicate uncomplexed urea. Dissociatedor tetragonal urea was identified by the presence of a spacing at3.95-4.01 A. which is the most intense spacing for urea. In additioninterplanar spacings for urea occur, in decreasing order of importanceat: 3.01-3.05, 2.13-2.18, 2.82-2.83 and 2.53-2.56 A. The higher therelative intensity of the spacing for tetragonal urea, using 3.95-4.01A., the more dissociated urea is present and the less stable is thecomplex. Therefore, the stability of a complex contaminated withdissociated urea is inversely proportional to the intensity of thespacing in the X-ray powder pattern for tetragonal urea when prepared asdescribed.

Spacings characteristic of complex formation in decreasing order ofimportance are: 4.11-4.15, 7.13-7.16, 3.39-3.40, 2.62-2.63, 2.06,3.27-3.28, 2.69-2.70 and 4.34-4.37 A. The interplanar spacing at3.56-3.57 A. is ambiguous being characteristic of both dissociated ureaand complex. These spacings with minor variations have been found to becharacteristic of all other urea inclusion compounds studied.

The intensity of the 3.95-4.01 A. spacing characteristic of dissociatedurea which first appears with the n-1,2-epoxyoctane (Item No. 3)complex, rapidly diminishes and disappears as we proceed to thecomplexes of the higher homologues. n-1,2-epoxynonane (Item No. 4) showsonly a slight (0.06) relative intensity for urea and n-1,2epoxydodecaneshows none. Although the corresponding n-1,2-epoxydecane andn-1,2-epoxyundecane were not available, their complexes could safely bepredicted to be free of urea since, without exception, the complexes ofthe higher homologues of any series studied which formed complexes weremore stable than all smaller homologues.

We claim:

1. A urea inclusion compound consisting of a complex of urea and amember of the group consisting of n-1,2-epoxyoctane, n-l,2-epoxynonane,and n-1,2-epoxydodecane.

2. A compound according to claim 1 wherein said member isn-1,2-epoxyoctane.

4. A compound according to claim 1 wherein said member isn-1,2-ep0xyd0decane.

References Cited by the Examiner NICHOLAS S. RIZZO, Primary Examiner.

3. A compound according to claim 1 wherein said 10 HENRY R. JILES,Examiner.

member is 11-1,2-epoxynonane.

1. A UREA INCLUSION COMPOUND CONSISTING OF A COMPLEX OF UREA AND AMEMBER OF THE GROUP CONSISTING OF N-1,2-EPOXYOCTANE, N-1,2-EPOXYNONANE,AND N-1,2-EPOXYDODECANE.